Method of treating cancer using selective estrogen receptor modulators

ABSTRACT

Disclosed herein are methods of treating subjects suffering from estrogen receptor positive cancer of the brain by administering a selective estrogen receptor degrader (SERM). Also disclosed are methods of treating a cancer that is resistant to an estrogen receptor modulator by administering a SERM.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/512,061, filed Oct. 10, 2014, which application claims priority toU.S. Provisional Application No. 61/971,627, filed Mar. 28, 2014, whichare incorporated herein by reference in their entireties.

STATEMENT OF GOVERNMENT INTEREST

Not applicable.

TECHNICAL FIELD

The present invention relates to methods of treating subjects sufferingfrom estrogen receptor positive cancer of the brain by administering aselective estrogen receptor modulator (SERM) to the subject. The presentinvention also relates to methods of treating subjects suffering from acancer that is resistant to an estrogen receptor modulator byadministering a SERM to the subject.

BACKGROUND

The estrogen receptor (ER) is a ligand dependent transcription factorwhose expression confers upon target cells the ability to respond toestrogens. In the absence of an activating ligand, ER resides in thecell in an inactive form within a large inhibitory protein complex. Uponbinding ligand, however, the receptor undergoes an activatingconformational change resulting in its release from the inhibitoryprotein complex, spontaneous dimerization and subsequent interactionwith enhancers located within target genes. Depending on the promotercontext of the bound receptor, and the co factors that are recruited tothe receptor in a particular cell, it can either positively ornegatively regulate target gene transcription. Thus, the same ER-ligandcomplex can have very different activities in different cells, anobservation that explains how estrogens, generally considered to bereproductive hormones, exhibit activities in bone, the cardiovascularsystem and in brain that are unrelated to reproductive function.

Whereas the molecular determinants of ER action differ considerablybetween target cells, it has been anticipated that the exploitation ofthis complexity will yield pharmaceuticals with process or tissueselective activities. The first evidence in support of this hypothesiscame from studies that probed the pharmacological activities of the‘antiestrogen’ tamoxifen. Identified as a high affinity antagonist of ERand developed as a treatment for ER-positive breast cancer, it soonbecame apparent that whereas tamoxifen could oppose estrogen action inthe breast it exhibited agonist activity in the bone, uterus and in thecardiovascular system. Reflecting this spectrum of activities, tamoxifenwas reclassified as a Selective Estrogen Receptor Modulator (SERM).

The increasing incidence of breast cancer brain metastases (BCBM) is anemerging challenge in the treatment of advanced breast cancer patients.The growing success of improved treatments of systemic disease hasallowed the manifestation of BCBM that previously would not haveimpacted the morbidity and mortality associated with breast cancer. Theprivileged environment of the brain, maintained by the relativelynon-porous blood brain barrier, presents a significant impediment to thesuccessful targeting of BCBM, leading to the use of gamma knife surgeryand/or whole brain radiation in an attempt to shrink or ablate brainlesions. The benefit of these treatments must be carefully balanced withneurological deficit as a result of treatment.

Although considerable advances have been made in targeting the estrogensignaling axis for the treatment of breast cancer and osteoporosis,similar progress has unfortunately not yet been accomplished in thedevelopment of safe and effective treatments for the climactericconditions or vasomotor disturbances that are associated with estrogendeprivation. There is considerable interest in developing novel SERMsthat can be used to treat vasomotor symptoms but which do not exhibitmitogenic activities in the breast or the uterus.

While tamoxifen and aromatase inhibitors have proven effective in thetreatment of estrogen receptor positive (ER+) breast cancer, theincidence of resistance remains significant, particularly in theadvanced/metastatic breast cancer setting. An additional class ofestrogen receptor targeting therapy, selective estrogen receptordegraders (SERDs), has recently come to prominence. These agents haveproven effective in pre-clinical models of breast cancers that areresistant to tamoxifen or aromatase inhibitors, leading to theirevaluation in clinical trials. However, these agents also do not readilypass the blood brain barrier, suggesting that they will be ineffectivein targeting BCBM. It would be beneficial to have other treatmentoptions that can penetrate the blood brain barrier and/or selectivelytarget tissue specific activities responsive to ER activation.

SUMMARY

The present invention is directed to a method of treating estrogenreceptor positive cancers of the brain in a subject. The methodcomprises administering a compound represented by the following formulaI:

-   -   wherein    -   TZ represents a C1-C4 alkylene group or —CR^(f′)R^(g′)—CH2-O—        wherein R^(f′) and R^(g′) independently represent hydrogen or a        C1-C6 alkyl group;    -   A represents a 5- to 14-membered heteroarylene group which may        have a substituent or a C6-C14 arylene group which may have a        substituent;    -   Y represents —CH₂—NR^(c)— wherein R^(c) represents hydrogen or a        C1-C6 alkyl group which may have a substituent;    -   ring G represents the following formula:

-   -   R′ represents 1 to 4 substituents independently selected from a        hydrogen atom, a C1-C6 alkoxy group, and a hydroxyl group;    -   a partial structure in formula (I) represented by the following        formula:

-   -   is

-   -   R″ represents hydrogen, a hydroxyl group that may be further        protected by a protecting group or a C1-C6 alkoxy group which        may have a substituent; and    -   R^(a) and R^(b) are the same as or different from each other and        each represents a hydrogen atom, a C1-C6 alkyl group which may        have a substituent, or a C3-C8 cycloalkyl group which may have a        substituent, or when R^(a) and R^(b) are bonded together, they        may form, together with the nitrogen atom that is adjacent to        R^(a) and R^(b), a 4- to 10-membered single ring which may have        a substituent; and    -   L represents a single bond,    -   or a salt thereof.

The cancer may be Breast cancer brain metastases, Astrocytoma, AtypicalTeratoid Rhabdoid Tumor (ATRT), Chondrosarcoma, Choroid PlexusCarcinoma, Craniopharyngioma, Ependymoma, Germ Cell Tumor, Glioblastoma,Glioma, Hemangioma, Juvenile Pilocytic Astrocytoma, Medulloblastoma,Meningioma, Neurofibroma, Neuronal and Mixed Neuronal-Glial Tumors,Oligoastrocytoma, Oligodendroglioma, Pineal Tumor, Pituitary Tumor,PNET—(primitive neuroectodermal tumor), Schwannoma, and Leptomeningealmetastases. R^(a) and R^(b) independently may represent a hydrogen atom,a methyl group, an ethyl group, a n-propyl group, an iso-propyl group, an-butyl group, an iso-butyl group, or a tert-butyl group. -T-Z— mayrepresents —CH₂CH₂— or —C(CH₃)₂CH₂O—. Y may represents —CH2-N(CH₂CH₃)—or —CH₂—N(CH₂CH₂OH)—. Each of R″ independently may represents a hydrogenatom or a methoxy group. R″ may represents a hydroxyl group. A mayrepresents a phenylene group. The compound may be(R)-6-{2-{ethyl[4-(2-ethylaminoethyl)benzyl]amino}-4-methoxyphenyl}-5,6,7,8-tetrahydronaphthalen-2-ol.An effective amount of the compound may be administered. The effectiveamount may comprise a high dosage. The high dosage may be more thanabout 20 mg/kg. The high dosage may be about 20 mg/kg to about 100mg/kg. The compound may be administered by oral administration,intravenous administration, intradermal injection, intramuscularinjection or subcutaneous injection. The method may further comprisingadministering an effective amount of at least one compound selected fromthe group consisting of a cyclin-dependent kinase 4 and 6 inhibitor(CDK4/6 inhibitor), an antiestrogen, a ligand of retinoic acid orretinoxic X receptor, an antiprogestin, an antiandrogen, vitamin D ormetabolite thereof, a farnesyl transferase inhibitor, a PPARα or gammaagonist and a MAP kinase inhibitor.

The present invention is directed to a method of treating breast cancerbrain metastasis in a subject. The method comprises administering acompound represented by the following formula I:

-   -   wherein    -   TZ represents a C1-C4 alkylene group or —CR^(f′)R^(g′)—CH2-O—        wherein R^(f′) and R^(g′) independently represent hydrogen or a        C1-C6 alkyl group;    -   A represents a 5- to 14-membered heteroarylene group which may        have a substituent or a C6-C14 arylene group which may have a        substituent;    -   Y represents —CH₂—NR^(c)— wherein R^(c) represents hydrogen or a        C1-C6 alkyl group which may have a substituent;    -   ring G represents the following formula:

-   -   R′ represents 1 to 4 substituents independently selected from a        hydrogen atom, a C1-C6 alkoxy group, and a hydroxyl group;    -   a partial structure in formula (I) represented by the following        formula:

-   -   is

-   -   R″ represents hydrogen, a hydroxyl group that may be further        protected by a protecting group or a C1-C6 alkoxy group which        may have a substituent; and    -   R^(a) and R^(b) are the same as or different from each other and        each represents a hydrogen atom, a C1-C6 alkyl group which may        have a substituent, or a C3-C8 cycloalkyl group which may have a        substituent, or when R^(a) and R^(b) are bonded together, they        may form, together with the nitrogen atom that is adjacent to        R^(a) and R^(b), a 4- to 10-membered single ring which may have        a substituent; and    -   L represents a single bond,    -   or a salt thereof.

R^(a) and R^(b) independently may represent a hydrogen atom, a methylgroup, an ethyl group, a n-propyl group, an iso-propyl group, a n-butylgroup, an iso-butyl group, or a tert-butyl group. -T-Z— may represents—CH₂CH₂— or —C(CH₃)₂CH₂O—. Y may represents —CH2-N(CH₂CH₃)— or—CH₂—N(CH₂CH₂OH)—. Each of R″ independently may represents a hydrogenatom or a methoxy group. R″ may represents a hydroxyl group. A mayrepresents a phenylene group. The compound may be(R)-6-{2-{ethyl[4-(2-ethylaminoethyl)benzyl]amino}-4-methoxyphenyl}-5,6,7,8-tetrahydronaphthalen-2-ol.An effective amount of the compound may be administered. The effectiveamount may comprise a high dosage. The high dosage may be more thanabout 20 mg/kg. The high dosage may be about 20 mg/kg to about 100mg/kg. The compound may be administered by oral administration,intravenous administration, intradermal injection, intramuscularinjection or subcutaneous injection. The method may further comprisingadministering an effective amount of at least one compound selected fromthe group consisting of a cyclin-dependent kinase 4 and 6 inhibitor(CDK4/6 inhibitor), an antiestrogen, a ligand of retinoic acid orretinoxic X receptor, an antiprogestin, an antiandrogen, vitamin D ormetabolite thereof, a farnesyl transferase inhibitor, a PPARα or gammaagonist and a MAP kinase inhibitor.

The present invention is directed to a method of treating a cancer in asubject, wherein the cancer is resistant to an estrogen receptormodulator. The method comprises administering a compound represented bythe following formula I:

-   -   wherein    -   TZ represents a C1-C4 alkylene group or —CR^(f′)R^(g′)—CH2-O—        wherein R^(f′) and R^(g′) independently represent hydrogen or a        C1-C6 alkyl group;    -   A represents a 5- to 14-membered heteroarylene group which may        have a substituent or a C6-C14 arylene group which may have a        substituent;    -   Y represents —CH₂—NR^(c)— wherein R^(c) represents hydrogen or a        C1-C6 alkyl group which may have a substituent;    -   ring G represents the following formula:

-   -   R′ represents 1 to 4 substituents independently selected from a        hydrogen atom, a C1-C6 alkoxy group, and a hydroxyl group;    -   a partial structure in formula (I) represented by the following        formula:

-   -   is

-   -   R″ represents hydrogen, a hydroxyl group that may be further        protected by a protecting group or a C1-C6 alkoxy group which        may have a substituent; and    -   R^(a) and R^(b) are the same as or different from each other and        each represents a hydrogen atom, a C1-C6 alkyl group which may        have a substituent, or a C3-C8 cycloalkyl group which may have a        substituent, or when R^(a) and R^(b) are bonded together, they        may form, together with the nitrogen atom that is adjacent to        R^(a) and R^(b), a 4- to 10-membered single ring which may have        a substituent; and    -   L represents a single bond,    -   or a salt thereof.

The cancer may be de novo resistant to the estrogen receptor modulator.The resistance to the estrogen receptor modulator may be acquired. Theestrogen receptor modulator may be a selective estrogen receptormodulator (SERM). The SERM may be tamoxifen, idoxifene, raloxifene orICI 182,780. The cancer may be breast, endometrial or ovarian cancer.The cancer may be breast cancer. R^(a) and R^(b) independently mayrepresent a hydrogen atom, a methyl group, an ethyl group, a n-propylgroup, an iso-propyl group, a n-butyl group, an iso-butyl group, or atert-butyl group. -T-Z— may represents —CH₂CH₂— or —C(CH₃)₂CH₂O—. Y mayrepresents —CH2-N(CH₂CH₃)— or —CH₂—N(CH₂CH₂OH)—. Each of R″independently may represents a hydrogen atom or a methoxy group. R″ mayrepresents a hydroxyl group. A may represents a phenylene group. Thecompound may be(R)-6-{2-{ethyl[4-(2-ethylaminoethyl)benzyl]amino}-4-methoxyphenyl}-5,6,7,8-tetrahydronaphthalen-2-ol.An effective amount of the compound may be administered. The effectiveamount may comprise a high dosage. The high dosage may be more thanabout 20 mg/kg. The high dosage may be about 20 mg/kg to about 100mg/kg. The compound may be administered by oral administration,intravenous administration, intradermal injection, intramuscularinjection or subcutaneous injection. The method may further comprisingadministering an effective amount of at least one compound selected fromthe group consisting of a cyclin-dependent kinase 4 and 6 inhibitor(CDK4/6 inhibitor), an antiestrogen, a ligand of retinoic acid orretinoxic X receptor, an antiprogestin, an antiandrogen, vitamin D ormetabolite thereof, a farnesyl transferase inhibitor, a PPARα or gammaagonist and a MAP kinase inhibitor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows treatment with(R)-6-{2-{ethyl[4-(2-ethylaminoethyl)benzyl]amino}-4-methoxyphenyl}-5,6,7,8-tetrahydronaphthalen-2-ol(“RAD 1901”) results in a dose dependent reduction in ER expression andactivity. A) MCF7 breast cancer cells were treated 4 hours as indicatedprior to western blot detection of ER and loading control cytokeratin(CK) 18. B) Ovariectomized mice bearing MCF7 xenograft tumors weretreated daily with RAD 1901 (“RAD”) or tamoxifen (“Tam”) in the contextof continued estrogen treatment.

FIG. 2 shows RAD1901 downregulates ERα expression. FIG. 2A shows ERαprotein expression in whole cell extracts pre-treated with transcriptionor translation inhibitors before treatment with RAD1901, analyzed byimmunoblot. FIG. 2B shows ERα mRNA expression in similarly treatedcells.

FIG. 3 shows the interaction between ER and conformation-specificpeptides in mammalian two-hybrid system.

FIG. 4 shows RAD 1901 exhibits dose dependent agonist/antagonistregulation of ER target genes.

DETAILED DESCRIPTION

The present disclosure provides a method of treating a subject sufferingfrom estrogen receptor positive cancer of the brain, such as BCBM, or acancer that is resistant to an estrogen receptor modulator, such astamoxifen resistant breast cancer. The methods involve administering tothe subject a SERM, such as RAD 1901. RAD 1901 exhibits desiredpharmacological activities and exhibits significant brain penetrancewhen evaluated in postmenopausal women, in particular a unique doseresponse, with lower doses of the drug being more effective at relievinghot flashes. RAD 1901 induces hot flashes in healthy postmenopausalwomen in a dose dependent manner, thus RAD 1901 may effectively inhibitestrogen receptor action in the brain.

Turnover of ERα is significantly increased upon binding RAD1901, anactivity that is more pronounced at higher drug concentrations (FIG. 1).This drug exhibits some of the characteristics that are generallyattributed to selective estrogen receptor degraders (SERDs). Thus, atlower doses RAD1901 exhibits partial agonist activity, i.e., SERMactivity, allowing for relief of hot flashes, but the SERD activity ofthe compound dominates when the receptor is exposed to higherconcentrations. The present disclosure describes in vitro the mechanismby which RAD1901 impacts ER expression and investigates the possibleresult of such action in vivo.

As exemplified below, RAD 1901 surprisingly has the ability to degradethe estrogen receptor. Both in vitro and in vivo studies have sinceshown that the antagonist activity of this ligand correlates withestrogen receptor degradation in a dose dependent manner. RAD 1901 alsoinhibits estrogen dependent growth of breast cancer xenograft tumors andmay be used to treat breast cancer, such as tamoxifen resistant breastcancer.

RAD 1901 is unique among both SERMs and SERDs in that this drugaccumulates in the brain, an environment in which SERM penetration hasbeen historically regarded as quite low. Estrogen receptor activity hasbeen found to be important in the growth of tumors resistant toaromatase inhibitors and/or tamoxifen, and treatment with SERDs has beenshown to have clinical benefit. While the revelation that RAD 1901exhibits SERD activity certainly suggests potential utility in thetreatment of progressing ER+ breast tumors, which was unappreciatedprior to the present disclosure, the targeting of ER activity for thetreatment of ER+ brain cancers represents a new frontier for the use ofboth SERMs and SERDs, as RAD 1901 represents the first SERM/SERD thatcan sufficiently penetrate the brain to exhibit efficacy. Because BCBMis generally diagnosed late in the disease progression of ER+ metastaticbreast cancer, patients will in general have already been treated withendocrine therapeutics (i.e. tamoxifen or aromatase inhibitors). Thus,while SERMs such as tamoxifen have low brain penetration and haveexhibited efficacy in anecdotal cases of BCBM that are detailed in theliterature, the SERD activity of RAD 1901 becomes key to the therapeuticpotential of this compound for treatment of BCBM, as SERDs have beenfound to be effective in breast cancers that are resistant to SERM oraromatase inhibitor therapy.

1. DEFINITIONS

The terms “comprise(s),” “include(s),” “having,” “has,” “can,”“contain(s),” and variants thereof, as used herein, are intended to beopen-ended transitional phrases, terms, or words that do not precludethe possibility of additional acts or structures. The singular forms“a,” “and” and “the” include plural references unless the contextclearly dictates otherwise. The present disclosure also contemplatesother embodiments “comprising,” “consisting of” and “consistingessentially of,” the embodiments or elements presented herein, whetherexplicitly set forth or not.

For the recitation of numeric ranges herein, each intervening numberthere between with the same degree of precision is explicitlycontemplated. For example, for the range of 6-9, the numbers 7 and 8 arecontemplated in addition to 6 and 9, and for the range 6.0-7.0, thenumber 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 areexplicitly contemplated.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art. In case of conflict, the present document, includingdefinitions, will control. Preferred methods and materials are describedbelow, although methods and materials similar or equivalent to thosedescribed herein can be used in practice or testing of the presentinvention. All publications, patent applications, patents and otherreferences mentioned herein are incorporated by reference in theirentirety. The materials, methods, and examples disclosed herein areillustrative only and not intended to be limiting.

The term “administration” or “administering,” as used herein refers toproviding, contacting, and/or delivery of the SERM by any appropriateroute to achieve the desired effect. These agents may be administered toa subject in numerous ways including, but not limited to, orally,ocularly, nasally, intravenously, topically, as aerosols, suppository,etc. and may be used in combination.

“Aromatase inhibitor” as used herein refers to a compound that targetsaromatase, which is an enzyme involved in the biosynthesis of estrogen.Aromatase inhibitors may block the production of estrogen or block theaction of estrogen on receptors.

“Blood brain barrier” or “BBB” as used herein refers to a highlyselective permeability barrier that separates the circulating blood fromthe brain extracellular fluid in the central nervous system. The bloodbrain barrier may prevent the certain drugs from entering brain tissueand is a limiting factor in the delivery of manyperipherally-administered agents to the central nervous system.

“Breast cancer” as used herein refers to a type of cancer thatoriginates from and develops in the breast. “Metastatic breast cancer”refers to breast cancer that spreads outside the breast to the lymphnodes, bones, or other areas.

“Breast Cancer Brain Metastases” and “BCBM” as used interchangeablyherein refer to breast cancer that has metastasized to the brain. BCBMmay occur in up to 10-15% of breast-cancer patients. BCBM may progressrapidly and can produce life-threatening complications such as increasedintracranial pressure, herniation of the brain and seizures.Radiotherapy is a treatment of BCBM as it halts tumor progressionquickly and can induce a response in the majority of patients.

“Cancer” as used herein refers to the uncontrolled and unregulatedgrowth of abnormal cells in the body. Cancerous cells are also calledmalignant cells. Cancer may invade nearby parts of the body and may alsospread to more distant parts of the body through the lymphatic system orbloodstream. Cancers include Adrenocortical Carcinoma, Anal Cancer,Bladder Cancer, Brain Tumor, Breast Cancer, Carcinoid Tumor,Gastrointestinal, Carcinoma of Unknown Primary, Cervical Cancer, ColonCancer, Endometrial Cancer, Esophageal Cancer, Extrahepatic Bile DuctCancer, Ewings Family of Tumors (PNET), Extracranial Germ Cell Tumor,Intraocular Melanoma Eye Cancer, Gallbladder Cancer, Gastric Cancer(Stomach), Extragonadal Germ Cell Tumor, Gestational TrophoblasticTumor, Head and Neck Cancer, Hypopharyngeal Cancer, Islet CellCarcinoma, Kidney Cancer (renal cell cancer), Laryngeal Cancer, AcuteLymphoblastic Leukemia, Leukemia, Acute Myeloid, Chronic LymphocyticLeukemia, Chronic Myelogenous Leukemia, Hairy Cell Leukemia, Lip andOral Cavity Cancer, Liver Cancer, Non-Small Cell Lung Cancer, Small CellLung Cancer, AIDS-Related Lymphoma, Central Nervous System (Primary)Lymphoma, Cutaneous T-Cell Lymphoma, Hodgkin's Disease Lymphoma,Non-Hodgkin's Disease Lymphoma, Malignant Mesothelioma, Melanoma, MerkelCell Carcinoma, Metasatic Squamous Neck Cancer with Occult Primary,Multiple Myeloma and Other Plasma Cell Neoplasms, Mycosis Fungoides,Myelodysplastic Syndrome, Myeloproliferative Disorders, NasopharyngealCancer, euroblastoma, Oral Cancer, Oropharyngeal Cancer, Osteosarcoma,Ovarian Epithelial Cancer, Ovarian Germ Cell Tumor, Pancreatic Cancer,Exocrine, Pancreatic Cancer, Islet Cell Carcinoma, Paranasal Sinus andNasal Cavity Cancer, Parathyroid Cancer, Penile Cancer, PituitaryCancer, Plasma Cell Neoplasm, Prostate Cancer, Rhabdomyosarcoma, RectalCancer, Renal Cell Cancer (cancer of the kidney), Transitional CellRenal Pelvis and Ureter, Salivary Gland Cancer, Sezary Syndrome, SkinCancer, Small Intestine Cancer, Soft Tissue Sarcoma, Testicular Cancer,Malignant Thymoma, Thyroid Cancer, Urethral Cancer, Uterine Cancer,Unusual Cancer of Childhood, Vaginal Cancer, Vulvar Cancer, and Wilms'Tumor.

The term “effective dosage” as used herein means a dosage of a drugeffective for periods of time necessary, to achieve the desiredtherapeutic result. An effective dosage may be determined by a personskilled in the art and may vary according to factors such as the diseasestate, age, sex, and weight of the individual, and the ability of thedrug to elicit a desired response in the individual. This term as usedherein may also refer to an amount effective at bringing about a desiredin vivo effect in an animal, mammal, or human, such as reducing and/orinhibiting the function of the estrogen receptor. A therapeuticallyeffective amount may be administered in one or more administrations(e.g., the agent may be given as a preventative treatment ortherapeutically at any stage of disease progression, before or aftersymptoms, and the like), applications or dosages and is not intended tobe limited to a particular formulation, combination or administrationroute. It is within the scope of the present disclosure that the SERMmay be administered at various times during the course of treatment ofthe subject. The times of administration and dosages used will depend onseveral factors, such as the goal of treatment (e.g., treating v.preventing), condition of the subject, etc. and can be readilydetermined by one skilled in the art.

“Estrogen dependent cancer” or “estrogen receptor positive cancer” asused interchangeably herein refers to a tumor that contains estrogenreceptor (ER) positive cells, i.e., cells that have estrogen receptors,and respond to the presence of estrogen with increased proliferation.Estrogen dependent cancers may include breast cancer, ovarian cancer, orendometrial cancer. “Estrogen receptor positive breast cancer” is a typeof breast cancer that is sensitive to estrogen.

“Estrogen receptor” or “ER” as used interchangeably herein refers to areceptor that is activated by the hormone estrogen and is a member ofthe nuclear hormone family of intracellular receptors. There are twodifferent isoforms of estrogen receptor, referred to as a (also referredto as “ERa”) and β (also referred to as “ERb”). ERa and ERb genes areencoded by ESR1 and ESR2 gene, respectively. Hormone-activated estrogenreceptors form dimers and may form homodimers or heterodimers. Both ERsare widely expressed in different tissue types.

“Estrogen-receptor downregulators” as used herein refers to a drug orcompound which binds and down-regulates the expression of anestrogen-receptor.

“Estrogen receptor negative breast cancer” or “Estrogen independentbreast cancer” as used interchangeably herein refers to a tumor thatdoes not contain estrogen receptor positive cells, i.e., cells that lackestrogen receptors, and does not depend on the presence of estrogen forongoing proliferation.

“HER2 intervention drug” or “HER2 inhibitor” as used interchangeablyherein refers to a compound that targets human Epidermal Growth FactorReceptor 2 (HER2). HER2 is a member of the epidermal growth factorreceptor family and is involved in the development and progression ofcertain aggressive types of breast cancer, such as estrogen dependentbreast cancer. A HER2 inhibitor may be a tyrosine kinase or a monoclonalantibody.

“Metastatic cancer” as used herein refers to a cancer that has spreadfrom the part of the body where it started (the primary site) to otherparts of the body.

“Progesterone receptor positive cancer” as used herein refers to a tumorthat contains progesterone receptor positive (PR+) cells, i.e., cellsthat have progesterone receptors, which respond to the presence ofprogesterone with increased proliferation.

“Selective estrogen receptor degraders” or “SERDs” as usedinterchangeably herein refers to a compound that interacts with an ERand induce a conformational change that results in the degradation ofthe receptor.

“Selective estrogen receptor modulators” or “SERMs” as usedinterchangeably herein refers to a compound that interacts with an ERand whose relative agonist/antagonist activities are manifest in a cellselective manner. The prevention of estrogen binding to the estrogenreceptor may lead to decreased proliferation of estrogen dependentcancer cells.

The term “subject”, “patient” or “subject in the method” as used hereininterchangeably, means any vertebrate, including, but not limited to, amammal (e.g., cow, pig, camel, llama, horse, goat, rabbit, sheep,hamsters, guinea pig, cat, dog, rat, and mouse, a non-human primate (forexample, a monkey, such as a cynomolgous or rhesus monkey, chimpanzee,etc.) and a human). In some embodiments, the subject or subject may be ahuman or a non-human. In some embodiments, the subject may be a humansubject at risk for developing or already suffering from cancer.

“Tamoxifen resistant breast cancer” as used herein refers to a breastcancer that does respond to treatment with tamoxifen.

“Treat”, “treating” or “treatment” are each used interchangeably hereinto describe reversing, alleviating, or inhibiting the progress of adisease, or one or more symptoms of such disease, to which such termapplies. Depending on the condition of the subject, the term also refersto preventing a disease, and includes preventing the onset of a disease,or preventing the symptoms associated with a disease. A treatment may beeither performed in an acute or chronic way. The term also refers toreducing the severity of a disease or symptoms associated with suchdisease prior to affliction with the disease. Such prevention orreduction of the severity of a disease prior to affliction refers toadministration of the SERM to a subject that is not at the time ofadministration afflicted with the disease. “Preventing” also refers topreventing the recurrence of a disease or of one or more symptomsassociated with such disease. “Treatment” and “therapeutically,” referto the act of treating, as “treating” is defined above.

2. METHODS OF TREATING CANCER WITH A SERM

The present invention is directed to methods of treating a subjectsuffering from cancer. The methods include administering a compound,i.e., SERM, having formula I:

wherein

TZ represents a C1-C4 alkylene group or —CR^(f′)R^(g′)—CH2-O— whereinR^(f′) and R^(g′) independently represent hydrogen or a C1-C6 alkylgroup;

A represents a 5- to 14-membered heteroarylene group which may have asubstituent or a C6-C14 arylene group which may have a substituent;

Y represents —CH₂—NR^(c)— wherein R^(c) represents hydrogen or a C1-C6alkyl group which may have a substituent; ring G represents thefollowing formula:

R′ represents 1 to 4 substituents independently selected from a hydrogenatom, a C1-C6 alkoxy group, and a hydroxyl group;

a partial structure in formula (I) represented by the following formula:

is

R″ represents hydrogen, a hydroxyl group that may be further protectedby a protecting group or a C1-C6 alkoxy group which may have asubstituent; and

R^(a) and R^(b) are the same as or different from each other and eachrepresents a hydrogen atom, a C1-C6 alkyl group which may have asubstituent, or a C3-C8 cycloalkyl group which may have a substituent,or when Ra and Rb are bonded together, they may form, together with thenitrogen atom that is adjacent to R^(a) and R^(b), a 4- to 10-memberedsingle ring which may have a substituent; and

L represents a single bond,

or a salt thereof.

In certain embodiments, R^(a) and R^(b) independently may represent ahydrogen atom, a methyl group, an ethyl group, a n-propyl group, aniso-propyl group, a n-butyl group, an iso-butyl group, or a tert-butylgroup. In certain embodiments, -T-Z— may represent —CH₂CH₂— or—C(CH₃)₂CH₂O—. In certain embodiments, Y may represent —CH2-N(CH₂CH₃)—or CH₂—N(CH₂CH₂OH)—. In certain embodiments, each of R″ mayindependently represent a hydrogen atom or a methoxy group. In certainembodiments, R″ may represent a hydroxyl group. In certain embodiments,A may represent a phenylene group. In certain embodiments, the compoundmay be(R)-6-{2-{ethyl[4-(2-ethylaminoethyl)benzyl]amino}-4-methoxyphenyl}-5,6,7,8-tetrahydronaphthalen-2-ol.Examples of other SERMS are described in U.S. Pat. No. 7,612,114, U.S.U.S. Pat. No. 7,960,412, U.S. Pat. No. 8,399,520, U.S. PatentPublication No. US 2009-0325930, and U.S. Patent Publication No. US2006-0116364, the contents of which are incorporated by reference intheir entirety. An effective amount of the compound may be administered.

(a) Dosages

In general, the dosage of administered SERM will vary depending uponsuch factors as the patient's age, weight, height, sex, general medicalcondition and previous medical history. Typically, it is desirable toprovide the recipient with a dosage of SERM which is in the range offrom about 1 pg/kg to 10 mg/kg (amount of agent/body weight of patient),although a lower or higher dosage also may be administered ascircumstances dictate. Dosage regimens may be adjusted to provide theoptimum desired response (e.g., a therapeutic or prophylactic response).For example, a single bolus may be administered, several divided dosesmay be administered over time or the dose may be proportionally reducedor increased as indicated by the exigencies of the therapeuticsituation. It is especially advantageous to formulate parenteralcompositions in dosage unit form for ease of administration anduniformity of dosage. Dosage unit form as used herein refers tophysically discrete units suited as unitary dosages for the mammaliansubjects to be tested; each unit containing a predetermined quantity ofactive compound calculated to produce the desired therapeutic effect inassociation with the required pharmaceutical carrier. The specificationfor the dosage unit forms of the present invention are dictated by anddirectly dependent on (a) the unique characteristics of the activecompound and the particular therapeutic or prophylactic effect to beachieved and (b) the limitations inherent in the art of compounding suchan active compound for the treatment of sensitivity in individuals.

An exemplary, non-limiting range for a therapeutically orprophylactically effective amount of the SERM is a dose of between 0.1and 200 mg/kg, for example between 0.1 and 10 mg/kg, or about 20 mg/kgto about 100 mg/kg. The therapeutically or prophylactically effectiveamount of the SERM may be between 1 and 200 mg/kg, 10 and 200 mg/kg, 20and 200 mg/kg, 50 and 200 mg/kg, 75 and 200 mg/kg, 100 and 200 mg/kg,150 and 200 mg/kg, 50 and 100 mg/kg, 5 and 10 mg/kg, or 1 and 10 mg/kg.It is to be noted that dosage values may vary with the type and severityof the condition to be alleviated.

In some embodiments, the SERM can be administered to a patient in anamount of about 10 mg/day to about 500 mg/day, about 10 mg/day to about200 mg/day (e.g., 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120,130, 140, 150, 160, 170, 180, 190, or 200 mg/day), 20 mg/day to about100 mg/day, 100 mg/day to about 200 mg/day, or about 200 mg/day to about500 mg/day (e.g., 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290,300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430,440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570,580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, or 700mg/day), inclusive of any single or multi-dose daily administrationregimen that falls within that total daily dose range. In someembodiments, the dose is from about 20 mg/day to about 100 mg/day.Additionally, one of ordinary skill in the art would also know how toadjust or modify variables such as dosage, dosage schedules, and routesof administration, as appropriate, for a given subject.

Further, the SERM dose may be determined by a person skilled in the artand may vary according to factors such as the disease state, age, sex,and weight of the individual, and the ability of the SERM to elicit adesired response in the individual. The dose is also one in which toxicor detrimental effects, if any, of the SERM are outweighed by thetherapeutically beneficial effects. It is to be further understood thatfor any particular subject, specific dosage regimens should be adjustedover time according to the individual need and the professional judgmentof the person administering or supervising the administration of thecompositions, and that dosage ranges set forth herein are exemplary onlyand are not intended to limit the scope or practice of the claimedcomposition.

(b) Rad 1901

The SERM may be RAD 1901. Although RAD 1901 may effectively treatvasomotor symptoms, its pharmacology is complex. Treatment of ERpositive breast cancer cells with RAD 1901 in MCF7 and BT483 cellsresulted in a pronounced dose dependent down regulation of the receptorexpression. RAD 1901 is a unique SERM in that it apparently has arelative agonist/antagonist activity in the brain that is determined bydose. At low doses RAD 1901, behaves as a SERM as it exhibits estrogenicactivity. At high doses, RAD 1901 may function as a SERD, reversing theresponse.

While targeting of the estrogen signaling axis has proven effective inthe treatment of breast cancer and osteoporosis, implementing a safetherapy that mitigates the vasomotor. While efforts are being made toaddress this unmet medical need using tissue specific estrogen complexes(TSECs) that combine estrogens and SERMs with the intention ofinhibiting estrogen action only in some tissues (i.e. breast anduterus), preliminary clinical data suggest that RAD 1901 may accomplishthe same medical goal without exposing the patient to estrogen. Theapparent dose dependent down regulation of ER by RAD1901 suggest that ata therapeutic (low) dose, RAD1901 may be mediating some level of agonistactivity, while a higher dose results in more extensive SERM activityand an effective blockade in estrogen signaling, thereby exacerbatingvasomotor symptoms.

In some embodiments, a low dose of RAD 1901 may be about 0 mg/kg toabout 25 mg/kg, about 0 mg/kg to about 20 mg/kg, about 0 mg/kg to about15 mg/kg, about 0 mg/kg to about 10 mg/kg, about 0 mg/kg to about 5mg/kg, about 1 mg/kg to about 25 mg/kg, about 1 mg/kg to about 20 mg/kg,about 1 mg/kg to about 15 mg/kg, about 1 mg/kg to about 10 mg/kg, about1 mg/kg to about 5 mg/kg, about 2 mg/kg to about 25 mg/kg, about 2 mg/kgto about 20 mg/kg, about 2 mg/kg to about 15 mg/kg, about 2 mg/kg toabout 10 mg/kg, about 2 mg/kg to about 5 mg/kg, about 3 mg/kg to about25 mg/kg, about 3 mg/kg to about 20 mg/kg, about 3 mg/kg to about 15mg/kg, about 3 mg/kg to about 10 mg/kg, about 3 mg/kg to about 5 mg/kg,about 4 mg/kg to about 25 mg/kg, about 4 mg/kg to about 20 mg/kg, about4 mg/kg to about 15 mg/kg, about 4 mg/kg to about 10 mg/kg, about 4mg/kg to about 5 mg/kg, about 5 mg/kg to about 25 mg/kg, about 5 mg/kgto about 20 mg/kg, about 5 mg/kg to about 15 mg/kg, about 5 mg/kg toabout 10 mg/kg, about 5 mg/kg to about 7.5 mg/kg. In some embodiments, alow dose of RAD 1901 may be less than about 25 mg/kg, about 24 mg/kg,about 23 mg/kg, about 22 mg/kg, about 21 mg/kg, about 20 mg/kg, about 19mg/kg, about 18 mg/kg, about 17 mg/kg, about 16 mg/kg, about 15 mg/kg,about 14 mg/kg, about 13 mg/kg, about 12 mg/kg, about 11 mg/kg, about 10mg/kg, about 9 mg/kg, about 8 mg/kg, about 7 mg/kg, about 6 mg/kg, about5 mg/kg, about 4 mg/kg, about 3 mg/kg, about 2 mg/kg, or about 1 mg/kg.

In some embodiments, a high dose of RAD 1901 may be about 15 mg/kg toabout 500 mg/kg, about 15 mg/kg to about 250 mg/kg, about 15 mg/kg toabout 200 mg/kg, about 15 mg/kg to about 150 mg/kg, about 15 mg/kg toabout 100 mg/kg, about 15 mg/kg to about 75 mg/kg, about 20 mg/kg toabout 500 mg/kg, about 20 mg/kg to about 250 mg/kg, about 20 mg/kg toabout 200 mg/kg, about 20 mg/kg to about 150 mg/kg, about 20 mg/kg toabout 100 mg/kg, about 20 mg/kg to about 75 mg/kg, about 25 mg/kg toabout 500 mg/kg, about 25 mg/kg to about 250 mg/kg, about 25 mg/kg toabout 200 mg/kg, about 25 mg/kg to about 150 mg/kg, about 25 mg/kg toabout 100 mg/kg, or about 25 mg/kg to about 75 mg/kg. In someembodiments, a high dose of RAD 1901 may be more than about 15 mg/kg, 20mg/kg, about 25 mg/kg, about 30 mg/kg, about 35 mg/kg, about 40 mg/kg,about 45 mg/kg, about 50 mg/kg, about 55 mg/kg, about 60 mg/kg, about 65mg/kg, about 70 mg/kg, about 75 mg/kg, about 80 mg/kg, about 85 mg/kg,about 90 mg/kg, about 95 mg/kg, about 100 mg/kg, about 105 mg/kg, about110 mg/kg, about 115 mg/kg, about 120 mg/kg, about 125 mg/kg, about 130mg/kg, about 135 mg/kg, about 140 mg/kg, about 145 mg/kg, about 150mg/kg, about 155 mg/kg, about 160 mg/kg, about 165 mg/kg, about 170mg/kg, about 175 mg/kg, about 180 mg/kg, about 185 mg/kg, about 190mg/kg, about 195 mg/kg, about 200 mg/kg, about 250 mg/kg, about 300mg/kg, about 350 mg/kg, about 400 mg/kg, about 450 mg/kg or about 500mg/kg.

In some embodiments, RAD1901 can be administered to a patient in anamount of about 10 mg/day to about 500 mg/day, about 10 mg/day to about200 mg/day (e.g., 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120,130, 140, 150, 160, 170, 180, 190, or 200 mg/day), 20 mg/day to about100 mg/day, 100 mg/day to about 200 mg/day, or about 200 mg/day to about500 mg/day (e.g., 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290,300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430,440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570,580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, or 700mg/day), inclusive of any single or multi-dose daily administrationregimen that falls within that total daily dose range. In someembodiments, the dose is from about 20 mg/day to about 100 mg/day.Additionally, one of ordinary skill in the art would also know how toadjust or modify variables such as dosage, dosage schedules, and routesof administration, as appropriate, for a given subject.

3. METHODS OF TREATING ESTROGEN RECEPTOR POSITIVE CANCER OF THE BRAIN

The methods described above may be used to treat an estrogen receptorpositive cancer of the brain. In some embodiments, the cancer mayinclude subtypes of brain tumors that may express ER, such as BreastCancer Brain Metastases (BCBM), Astrocytoma, Chondrosarcoma,Craniopharyngioma, Glioblastoma, Glioma, Hemangioma, Medulloblastoma,Meningioma, Neurofibroma, Neuronal and Mixed Neuronal-Glial Tumors,Oligoastrocytoma, Pituitary Tumor, PNET—(primitive neuroectodermaltumor), Schwannomak, or Leptomeningeal metastases. In some embodiments,the cancer may be other cancers such as Atypical Teratoid Rhabdoid Tumor(ATRT), Choroid Plexus Carcinoma, Ependymoma, Germ Cell Tumor, JuvenilePilocytic Astrocytoma, Oligodendroglioma, or Pineal Tumor.

(a) Breast Cancer Brain Metastases

The methods described above may be used to treat a subject sufferingfrom breast cancer brain metastases. 10-20% of breast cancer patientsultimately experience breast cancer metastasis to the brain, i.e., BCBM.30-40% of BCBM express ER. ER expression is retained in 50-65% of BCBMthat arise from ER+/PR+ tumors, despite treatment of the initial tumorwith endocrine therapies. As many as 50% of BCBM express the estrogenreceptor, and the brain is an environment rich in aromatase activity,suggesting that estrogen levels and signaling may be of importance inthe establishment and maintenance of BCBM. Therefore, the availabilityof the SERM, such as RAD 1901 or a similar SERM with significant brainpenetrance, that can induce estrogen receptor turnover in BCBM mayprovide therapeutic benefit in the treatment of BCBM.

(b) Astrocytoma

Astrocytoma is a type of cancer of the brain that originate inastrocytes, which are a particular kind of glial cells, start-shapedbrains cells in the cerebrum. Low ERb expression has been shown to beassociated with the progression of astrocytoma.

(c) Chondrosarcoma

Chondrosarcoma is a type of tumor that affects the bones and joints.Chondrosarcoma grow from the types of cells that make cartilage in theskull. In the head, these tumors grow inside the bones at the base ofthe back part of the skull and may be very close to the nerves and bloodvessels around the brainstem. ER is present and active in chondrosarcomatumors.

(d) Craniopharyngioma

Craniopharyngioma is a benign tumor that develops near the pituitarygland. ER may be present in craniopharyngioma and may be associated withimproved disease prognosis.

(e) Glioblastoma Multiforme

Glioblastoma multiforme, also known as “glioblastoma,” is the mostcommon and most aggressive malignant primary brain tumor in humans,involving glial cells and accounting for 52% of all functional tissuebrain tumor cases and 20% of all intracranial tumors. Glioblastoma mayexpress both ERs, which may play a role in etiology and treatment.

(f) Glioma

Glioma is a type of tumor that starts in the brain or spine and arisesfrom glial cells. Gliomas make up approximately 30% of all brain andcentral nervous system tumors and 80% of all malignant brain tumors.Glioma may express both ERs, which may play a role in etiology andtreatment. Glioma may be responsive to tamoxifen treatment.

(g) Hemangioma

Hemangioma is a benign and usually self-involuting tumor (swelling orgrowth) of the endothelial cells that line blood vessels. Hemangioma ischaracterized by increased number of normal or abnormal vessels filledwith blood. Human vascular endothelial cells express ER isoforms and areresponsive to tamoxifen treatment. Hemangioma may be intracranialhemangiomas or cutaneous hemangiomas.

(h) Medulloblastoma

Medulloblastoma is a highly malignant primary brain tumor thatoriginates in the cerebellum or posterior fossa. Medulloblastomas mayoriginate from immature or embryonal cells at their earliest stage ofdevelopment. Medulloblastoma may express ER isoforms. ER isoforms areassociated with growth and migration of these cells.

(i) Meningioma

Meningiomas are a diverse set of tumors arising from the meninges, i.e.,the membranous layers surrounding the central nervous system. Meningiomamay express both ER isoforms. Meningioma may be responsive to tamoxifentreatment.

(j) Neurofibroma

Neurofibroma is a benign nerve sheath tumor in the peripheral nervoussystem. Neurofibromas arise from nonmyelinating-type Schwann cells thatexhibit biallelic inactivation of the NF1 gene that codes for theprotein neurofibromin. Neurofibroma may be ER positive.

(k) Neuronal & Mixed Neuronal-Glial Tumors

Neuronal & Mixed Neuronal-Glial Tumors are rare, benign tumors that comefrom ganglion-type cells, i.e., groups of nerve cells. ER may be presentin these tumors.

(l) Oligoastrocytoma

Oligoastrocytomas are a subset of brain tumors that present with anappearance of mixed glial cell origin, astrocytoma andoligodendroglioma. Oligoastrocytoma may have a lasting response totamoxifen treatment.

(m) Pituitary Tumor

A pituitary tumor is an abnormal growth in the pituitary gland. Both ERaand ERb may be detected in pituitary tumors.

(n) Primitive Neuroestodermal Tumor (PNET)

Primitive neuroestodermal tumor is a neural crest tumor. The majority ofthe cells in the PNET are derived from neuroectoderm, but have notdeveloped and differentiated in the way a normal neuron would, and sothe cells appear “primitive. ERa may be present and may increasemetastatic potential via extracellular signal-regulated Kinase (ERK)activation.

(o) Schwannoma

Schwannoma (also known as an “neurilemmoma,” “neurinoma,”“neurolemmoma,” and “Schwann cell tumor”) is a benign nerve sheath tumorcomposed of Schwann cells, which normally produce the insulating myelinsheath covering peripheral nerves. Schwannoma may express ERa.

(p) Leptomeningeal Metastases

Leptomeningeal metastases is breast cancer metastasis to the membranes(meninges) surrounding the brain and spinal cord. A durable response hasbeen observed in patient(s) treated with aromatase inhibitors, whichsuggests possible responsiveness to ER targeted therapies.

4. METHODS OF TREATING A CANCER THAT IS RESISTANT TO AN ESTROGENRECEPTOR MODULATOR

The methods described above may be used to treat a cancer that isresistant to an estrogen receptor modulator. The resistance to theestrogen receptor modulator may be acquired. The estrogen receptormodulator may be a selective estrogen receptor modulator (SERM). TheSERM may be tamoxifen, idoxifene, raloxifene or ICI 182,780. The cancermay be breast, endometrial or ovarian cancer. The cancer may betamoxifen resistant breast cancer.

5. MECHANISMS OF DELIVERY

The SERM may be formulated to be compatible with its intended route ofadministration. Examples of routes of administration include, but arenot limited to, parenteral, e.g., intravenous, intradermal,subcutaneous, oral, intranasal (e.g., inhalation), transdermal (e.g.,topical), transmucosal, and rectal administration. In a specificembodiment, the SERM is formulated in accordance with routine proceduresas a pharmaceutical composition adapted for intravenous, subcutaneous,intramuscular, oral, intranasal, or topical administration to humanbeings. Typically, compositions for intravenous administration aresolutions in sterile isotonic aqueous buffer. Where necessary, thecomposition may also include a solubilizing agent and a local anestheticsuch as lignocaine to ease pain at the site of the injection.

Various delivery systems are known and can be used to administer one ormore SERMs or the combination of one or more SERMs and a prophylacticagent or therapeutic agent useful for preventing, managing, treating, orameliorating a disorder or one or more symptoms thereof, e.g.,encapsulation in liposomes, microparticles, microcapsules,receptor-mediated endocytosis (see, e.g., Wu and Wu, J. Biol. Chem.262:4429-4432 (1987)), etc. Methods of administering a prophylactic ortherapeutic agent of the SERM include, but are not limited to,parenteral administration (e.g., intradermal, intramuscular,intraperitoneal, intravenous and subcutaneous), epidural administration,intratumoral administration, and mucosal administration (e.g.,intranasal and oral routes).

6. COMBINATION TREATMENTS

The methods described above may include a combination treatment of thecompound of formula I with other drugs and/or other conventional cancertherapies, such as hormone therapy.

(a) Combination Drugs

The methods may further include administering an effective amount of atleast one compound of a cyclin-dependent kinase 4 and 6 inhibitor(CDK4/6 inhibitor), an antiestrogen, a ligand of retinoic acid orretinoic X receptor, an antiprogestin, an antiandrogen, vitamin D ormetabolite thereof, a farnesyl transferase inhibitor, a PPARα or gammaagonist and a MAP kinase inhibitor.

(b) Conventional Cancer Therapies

Conventional cancer therapies may include surgery, radiation therapy,chemotherapy, hormone therapy, and targeted therapy. Examples of surgeryinclude open craniotomy with maximal excision, which may be followed byradiation therapy. Examples of radiation therapy include whole-brainirradiation, fractionated radiotherapy, and radiosurgery, such asstereotactic radiosurgery, e.g., Gamma Knife radiosurgery. Examples ofchemotherapy include anthracyclines, such as doxorubicin (Adriamycin,Doxil), epirubicin (Ellence), and daunorubicin (Cerubidine, DaunoXome),capecitabine (Xeloda), carboplatin (Paraplatin), cisplatin,cyclophosphamide (Cytoxan), eribulin (Halaven), fluorouracil (alsocalled 5-fluorouracil or 5-FU; Adrucil), gemcitabine (Gemzar),ixabepilone (Ixempra), methotrexate (Amethopterin, Mexate, Folex),mitoxantrone (Novantrone), mutamycin (Mitomycin), taxanes, such aspaclitaxel (Taxol, Abraxane), and docetaxel (Taxotere), thiotepa(Thioplex), vincristine (Oncovin, Vincasar PES, Vincrex), andvinorelbine (Navelbine). Examples of targeted therapy includetrastuzumab (Herceptin), lapatinib (Tykerb), bevacizumab (Avastin),pertuzumab (Perjeta), and everolimus (Afinitor).

i. Endocrine Therapy (Hormone Therapy)

Endocrine therapy, also known as hormonal therapy, hormone therapy, andhormone treatment, is a treatment that adds, blocks, or removeshormones. For example, hormones may be given to adjust low hormonelevels. Synthetic hormones or other drugs may be given to block thebody's natural hormones to slow or stop the growth of certain cancers(such as prostate and breast cancer). Endocrine therapy may also includesurgery to remove the gland that makes a certain hormones.

Examples of hormone therapy include selective estrogen receptormodulators (SERMs), such as tamoxifen, raloxifene, endoxifene,toremifene, lasofoxifene, pipendoxifene, bazedoxifene, and ospemifene,aromatase inhibitors, such anastrozole, letrozole, exemestane,formestane, fadrozole, aminoglutethimide, and testolactone, a HER2intervention drug, such as a HER2 inhibitor, such as Herceptin(trastuzumab), pertuzumab, and lapatinib, and estrogen-receptordownregulators, such as fulvestrant (ICI 182,780).

7. SUBJECT OR SUBJECT IN THE METHOD

The methods described above are directed to treating a subject with aSERM. The subject treated by the methods described above may be asubject or patient suffering from or at risk of suffering from anestrogen receptor positive cancer of the brain, such as BCBM, or acancer that is resistant to an estrogen receptor modulator, such astamoxifen resistant breast cancer. The subject may be diagnosed oridentified as having or at risk of having cancer using known methods andassays, such as a biopsy. The subject may be treated with SERM alone orin combination with another drug and/or conventional cancer therapy, asdescribed above. The subject may be treated with the SERM as aneoadjuvant therapy or post-surgery. The present invention has multipleaspects, illustrated by the following non-limiting examples.

8. EXAMPLES

The foregoing may be better understood by reference to the followingexamples, which are presented for purposes of illustration and are notintended to limit the scope of the invention.

Example 1 In Vitro Analysis of ER Degradation

48 hours prior to treatment, MCF7 cells were plated in phenol red freeDMEM/F12 media supplemented with 8% charcoal stripped fetal bovineserum, non-essential amino acids, and sodium pyruvate. After 20 hours oftreatment with the indicated ligands, i.e., estradiol (“E2”;Sigma-Aldrich), antiestrogen ICI 182,780 (“ICI”; Sigma-Aldrich), and4-hydroxytamoxifen (“4OHT”; Sigma-Aldrich), (0-1 μM), cells were washedand lysed in RIPA lysis buffer (50 mM Tris, pH 8, 150 mM NaCl, 1%IGEPAL, 0.02% SDS, 0.5% sodium deoxycholate, 1 mM EDTA). 50 ug ofcleared lysate was resolved by SDS-PAGE and analyzed by immunoblotdetection of ERα or cytokeratin 18 (loading control), as illustrated inFIG. 1A.

Example 2 In Vivo Analysis of RAD 1901 in MCF7 Xenograft Tumors

A total of 90 female Nu/Nu mice were ovariectomized and implantedsubcutaneous simultaneously with an estrogen pellet (Innovative Researchof America) releasing 0.72 mg estradiol (E2) over 60 days. 2 days lateran approximately 6 mm³ fragment of an MCF7 xenograft tumor (isolatedfrom a recently sacrificed estrogen treated nu/nu mouse) was insertedsubcutaneous into the axial mammary gland. Tumor growth (by calipermeasurement) and animal body weight were monitored 3× weekly until tumorvolume reached ˜0.2 cm³. Mice (n˜10) were randomized to the followinggroups: estrogen control (corn oil vehicle), E2+RAD 1901 (20 mg/kg;Radius Health, Inc.), E2+Tamoxifen (20 mg/kg; Sigma-Aldrich). Treatmentswere formulated in sterile corn oil and were administered daily bysubcutaneous injection. After 3 weeks of treatments, animals wereeuthanized and serum and tissues saved for analysis. FIG. 1B depictstumor volume analyzed using non-linear curve fit and exponential growthcalculation (Graphpad Prism), followed by two-way ANOVA and Bonferronianalysis.

Example 3 Mechanism by which RAD1901 Downregulates ER Expression

While the reduced levels of ER following treatment with RAD1901 resultsin receptor degradation, whether the drug influences the transcriptionalactivity of the gene encoding ER was determined. (FIG. 2) MCF7 cellswere pre-treated with Vehicle (Veh) or translation (cyclohexamide—CHX,10 μg/ml), proteasome (MG132, 30 μM) or transcription (ActinomycinD—Actin. D, 100 ng/ml) inhibitors for 2 hours prior to 6 hours oftreatment with RAD 1901 (0.1 or 1 μM), or 0.1 μM ICI 182,780 (ICI) orraloxifene (Ral). FIG. 2A shows ERα protein expression in whole cellextracts was analyzed by immunoblot, as in Example 1. FIG. 2B showscells treated, as indicated, were washed in PBS prior to lysis. RNAisolation (BioRad) and reverse transcription (iScript; BioRad) wereperformed per kit manufacturer's instructions. qRT-PCR of cDNA was doneusing iQ SYBR Green Supermix (Bio-Rad) per kit instructions andperformed using the iCycler optical system with associated software(Bio-Rad). mRNA abundance was calculated using the ΔΔCT method tonormalize ERα mRNA expression to similarly detected housekeeping gene36B4.

Example 4 Conformational Changes Induced in ER as a Consequence ofBinding of RAD1901

A series of short peptides whose ability to interact with ERα isinfluenced by the nature of the bound ligand were previously identified(see Chang et al. Methods Enzymol. (2003) 364:118-42; Huang et al. MolEndocrinol. (2002) 16(8):1778-92; Connor et al. Cancer Res. (2001)61(7):2917-22; Chang et al. Mol Cell Biol. (1999) 19(12):8226-39; andNorris et al. Science (1999) 285(5428):744-6). The interaction of these“conformational probes” can be measured in vitro or within intact cellsand thus enables the definition of ligand induced conformational changesin the receptor. This is significant, since differences in receptorconformation facilitate the engagement of different coregulatoryproteins resulting in different pharmacological activities. Applicationof this technology has led to the determination that their impact onreceptor structure is a distinguishing feature of ER ligands.

FIG. 3 shows that Rad 1901 induces a unique conformation of ERα as shownin the interaction between ER and conformation-specific peptides in amammalian two-hybrid system. Triplicate wells of SKBR3 cells weretransfected (Lipofectin per manufacturer's instructions) with plasmidsexpressing ERα fused to VP16 together with Gal4DBD alone (control) orfused to ER interacting peptides noted on the horizontal axis. Cellswere then treated with Rad 1901 (1 nM-1 μM) or the indicated ER ligands(100 nM). Interaction of ERα with the Gal4DBD peptide constructs wasdetected through activation of a Gal4 responsive luciferase reporterconstruct and was normalized to detected β-galactosidase activitygenerated by a co-transfected constitutive expression vector. Ligandclasses recognized by each probe are indicated below the graph.

Example 5 RAD1901 Possesses Dose Dependent Agonist and/or AntagonistPotential

The complex pharmacological activities exhibited by RAD 1901 suggestthat it will exhibit a unique gene expression profile in target cells. Arecent extensive microarray analysis has identified “sentinel” subsetsof ER-responsive genes that can differentiate between ER agonists, SERMsand SERDs. For example, some of these are responsive to only the SERMtamoxifen, while others display a graded response to SERMs with varyingagonist/antagonist potential, and yet others are repressed by agonistsor SERMs and are induced only by SERDs. RAD1901 exhibits dose dependentagonist/antagonist regulation of ER transactivation of target genes(FIG. 4). MCF7 breast cancer cells were treated 24 hours with RAD 1901(0-1 μM) in the presence or absence of 17β-estradiol (1 nM). RNAisolation and the analysis of the expression of target genes Anteriorgradient protein 2 (AGR2) and KCNK6 was conducted as in Example 3.

It is understood that the foregoing detailed description andaccompanying examples are merely illustrative and are not to be taken aslimitations upon the scope of the invention, which is defined solely bythe appended claims and their equivalents.

Various changes and modifications to the disclosed embodiments will beapparent to those skilled in the art. Such changes and modifications,including without limitation those relating to the chemical structures,substituents, derivatives, intermediates, syntheses, compositions,formulations, or methods of use of the invention, may be made withoutdeparting from the spirit and scope thereof.

For reasons of completeness, various aspects of the invention are setout in the following numbered clauses:

Clause 1. A method of treating estrogen receptor positive cancers of thebrain in a subject, the method comprising administering a compoundrepresented by the following formula I:

-   -   wherein    -   TZ represents a C1-C4 alkylene group or —CR^(f′)R^(g′)—CH2-O—        wherein R^(f′) and R^(g′) independently represent hydrogen or a        C1-C6 alkyl group;    -   A represents a 5- to 14-membered heteroarylene group which may        have a substituent or a C6-C14 arylene group which may have a        substituent;    -   Y represents —CH₂—NR^(c)— wherein R^(c) represents hydrogen or a        C1-C6 alkyl group which may have a substituent;    -   ring G represents the following formula:

-   -   R′ represents 1 to 4 substituents independently selected from a        hydrogen atom, a C1-C6 alkoxy group, and a hydroxyl group;    -   a partial structure in formula (I) represented by the following        formula:

-   -   is

-   -   R″ represents hydrogen, a hydroxyl group that may be further        protected by a protecting group or a C1-C6 alkoxy group which        may have a substituent; and    -   R^(a) and R^(b) are the same as or different from each other and        each represents a hydrogen atom, a C1-C6 alkyl group which may        have a substituent, or a C3-C8 cycloalkyl group which may have a        substituent, or when R^(a) and R^(b) are bonded together, they        may form, together with the nitrogen atom that is adjacent to        R^(a) and R^(b), a 4- to 10-membered single ring which may have        a substituent; and    -   L represents a single bond,    -   or a salt thereof.

Clause 2. The method of clause 1, wherein the cancer is Breast cancerbrain metastases, Astrocytoma, Atypical Teratoid Rhabdoid Tumor (ATRT),Chondrosarcoma, Choroid Plexus Carcinoma, Craniopharyngioma, Ependymoma,Germ Cell Tumor, Glioblastoma, Glioma, Hemangioma, Juvenile PilocyticAstrocytoma, Medulloblastoma, Meningioma, Neurofibroma, Neuronal andMixed Neuronal-Glial Tumors, Oligoastrocytoma, Oligodendroglioma, PinealTumor, Pituitary Tumor, PNET—(primitive neuroectodermal tumor),Schwannoma, and Leptomeningeal metastases.

Clause 3. A method of treating breast cancer brain metastasis in asubject, the method comprising administering a compound represented bythe following formula I:

-   -   wherein    -   TZ represents a C1-C4 alkylene group or —CR^(f′)R^(g′)—CH2-O—        wherein R^(f′) and R^(g′) independently represent hydrogen or a        C1-C6 alkyl group;    -   A represents a 5- to 14-membered heteroarylene group which may        have a substituent or a C6-C14 arylene group which may have a        substituent;    -   Y represents —CH₂—NR^(c)— wherein R^(c) represents hydrogen or a        C1-C6 alkyl group which may have a substituent;    -   ring G represents the following formula:

-   -   R′ represents 1 to 4 substituents independently selected from a        hydrogen atom, a C1-C6 alkoxy group, and a hydroxyl group;    -   a partial structure in formula (I) represented by the following        formula:

-   -   is

-   -   R″ represents hydrogen, a hydroxyl group that may be further        protected by a protecting group or a C1-C6 alkoxy group which        may have a substituent; and    -   R^(a) and R^(b) are the same as or different from each other and        each represents a hydrogen atom, a C1-C6 alkyl group which may        have a substituent, or a C3-C8 cycloalkyl group which may have a        substituent, or when R^(a) and R^(b) are bonded together, they        may form, together with the nitrogen atom that is adjacent to        R^(a) and R^(b), a 4- to 10-membered single ring which may have        a substituent; and    -   L represents a single bond,    -   or a salt thereof.

Clause 4. A method of treating a cancer in a subject, wherein the canceris resistant to an estrogen receptor modulator, the method comprisingadministering a compound represented by the following formula I:

-   -   wherein    -   TZ represents a C1-C4 alkylene group or —CR^(f′)R^(g′)—CH2-O—        wherein R^(f′) and R^(g′) independently represent hydrogen or a        C1-C6 alkyl group;    -   A represents a 5- to 14-membered heteroarylene group which may        have a substituent or a C6-C14 arylene group which may have a        substituent;    -   Y represents —CH₂—NR^(c)— wherein R^(c) represents hydrogen or a        C1-C6 alkyl group which may have a substituent;    -   ring G represents the following formula:

-   -   R′ represents 1 to 4 substituents independently selected from a        hydrogen atom, a C1-C6 alkoxy group, and a hydroxyl group;    -   a partial structure in formula (I) represented by the following        formula:

-   -   is

-   -   R″ represents hydrogen, a hydroxyl group that may be further        protected by a protecting group or a C1-C6 alkoxy group which        may have a substituent; and    -   R^(a) and R^(b) are the same as or different from each other and        each represents a hydrogen atom, a C1-C6 alkyl group which may        have a substituent, or a C3-C8 cycloalkyl group which may have a        substituent, or when R^(a) and R^(b) are bonded together, they        may form, together with the nitrogen atom that is adjacent to        R^(a) and R^(b), a 4- to 10-membered single ring which may have        a substituent; and    -   L represents a single bond,    -   or a salt thereof.

Clause 5. The method of clause 4, wherein the cancer is de novoresistant to the estrogen receptor modulator.

Clause 6. The method of clause 4, wherein the resistance to the estrogenreceptor modulator is acquired.

Clause 7. The method of clause 4, wherein the estrogen receptormodulator is a selective estrogen receptor modulator (SERM).

Clause 8. The method of clause 7, wherein the SERM is tamoxifen,idoxifene, raloxifene or ICI 182,780.

Clause 9. The method of any one of clauses 4-8, wherein the cancer isbreast, endometrial or ovarian cancer.

Clause 10. The method of any one of clauses 4-9, wherein the cancer isbreast cancer.

Clause 11. The method of any one of clauses 1-10, wherein R^(a) andR^(b) independently represent a hydrogen atom, a methyl group, an ethylgroup, a n-propyl group, an iso-propyl group, a n-butyl group, aniso-butyl group, or a tert-butyl group.

Clause 12. The method of any one of clauses 1-10, wherein -T-Z—represents —CH₂CH₂— or —C(CH₃)₂CH₂O—.

Clause 13. The method of any one of clauses 1-10, wherein Y represents—CH2-N(CH₂CH₃)— or —CH₂—N(CH₂CH₂OH)—.

Clause 14. The method of any one of clauses 1-10, wherein each of R″independently represents a hydrogen atom or a methoxy group.

Clause 15. The method of any one of clauses 1-10, wherein R″ representsa hydroxyl group.

Clause 16. The method of any one of clauses 1-10, wherein A represents aphenylene group.

Clause 17. The method of any one of clauses 1-10, wherein the compoundis(R)-6-{2-{ethyl[4-(2-ethylaminoethyl)benzyl]amino}-4-methoxyphenyl}-5,6,7,8-tetrahydronaphthalen-2-ol.

Clause 18. The method of any one of clauses 1-10, wherein an effectiveamount of the compound is administered.

Clause 19. The method of any one of clauses 1-10, wherein the effectiveamount comprises a high dosage.

Clause 20. The method of clause 19, wherein the high dosage is more thanabout 20 mg/kg.

Clause 21. The method of clause 19 or 20, wherein the high dosage isabout 20 mg/kg to about 100 mg/kg.

Clause 22. The method of any one of clauses 1-10, wherein the compoundis administered by oral administration, intravenous administration,intradermal injection, intramuscular injection or subcutaneousinjection.

Clause 23. The method of any one of clauses 1-10, further comprisingadministering an effective amount of at least one compound selected fromthe group consisting of a cyclin-dependent kinase 4 and 6 inhibitor(CDK4/6 inhibitor), an antiestrogen, a ligand of retinoic acid orretinoxic X receptor, an antiprogestin, an antiandrogen, vitamin D ormetabolite thereof, a farnesyl transferase inhibitor, a PPARα or gammaagonist and a MAP kinase inhibitor.

What is claimed is:
 1. A method of treating an estrogen receptorpositive breast cancer in a subject, wherein the estrogen receptorpositive breast cancer is resistant to an estrogen receptor modulator,the method comprising administering a composition comprising a compoundof(R)-6-{2-{ethyl[4-(2-ethylaminoethyl)benzyl]amino}-4-methoxyphenyl}-5,6,7,8-tetrahydronaphthalen-2-ol.2. The method of claim 1, wherein the estrogen receptor positive breastcancer is de novo resistant to the estrogen receptor modulator.
 3. Themethod of claim 1, wherein the resistance to the estrogen receptormodulator is acquired.
 4. The method of claim 1, wherein the estrogenreceptor modulator is a selective estrogen receptor modulator (SERM). 5.The method of claim 4, wherein the SERM is tamoxifen, idoxifene,raloxifene or ICI 182,780.
 6. The method of claim 1, wherein aneffective amount of the composition is administered.
 7. The method ofclaim 1, wherein the effective amount comprises a high dosage.
 8. Themethod of claim 7, wherein the high dosage is more than about 20 mg/kg.9. The method of claim 1, wherein the composition is administered byoral administration, intravenous administration, intradermal injection,intramuscular injection or subcutaneous injection.
 10. The method ofclaim 1, further comprising administering an effective amount of atleast one compound selected from the group consisting of acyclin-dependent kinase 4 and 6 inhibitor (CDK4/6 inhibitor), anantiestrogen, a ligand of retinoic acid or retinoxic X receptor, anantiprogestin, an antiandrogen, vitamin D or metabolite thereof, afarnesyl transferase inhibitor, a PPARα or gamma agonist and a MAPkinase inhibitor.